From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH v4] igb_uio: fix possible mmap failure for Linux >= v4.5 Date: Sun, 10 Jul 2016 15:58:19 +0200 Message-ID: <3923466.ri2s8GbSSX@xps13> References: <1467385678-16205-1-git-send-email-ferruh.yigit@intel.com> <1467730852-12040-1-git-send-email-ferruh.yigit@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org, Stephen Hemminger To: Ferruh Yigit Return-path: Received: from mail-wm0-f53.google.com (mail-wm0-f53.google.com [74.125.82.53]) by dpdk.org (Postfix) with ESMTP id 0BC6411DE for ; Sun, 10 Jul 2016 15:58:22 +0200 (CEST) Received: by mail-wm0-f53.google.com with SMTP id k123so64883486wme.0 for ; Sun, 10 Jul 2016 06:58:22 -0700 (PDT) In-Reply-To: <1467730852-12040-1-git-send-email-ferruh.yigit@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 2016-07-05 16:00, Ferruh Yigit: > mmap the iomem range of the PCI device fails for kernels that > enabled CONFIG_IO_STRICT_DEVMEM option: > > EAL: pci_map_resource(): > cannot mmap(39, 0x7f1c51800000, 0x100000, 0x0): > Invalid argument (0xffffffffffffffff) > > CONFIG_IO_STRICT_DEVMEM is introduced in Linux v4.5 and not enabled > by default: > Linux commit: 90a545e restrict /dev/mem to idle io memory ranges > > As a workaround igb_uio can stop reserving PCI memory resources, from > kernel point of view iomem region looks like idle and mmap works > again. This matches uio_pci_generic usage. > > With this update device iomem range is not protected against any > other kernel drivers or userspace access. But this shouldn't > be a problem for dpdk usage module since purpose of the igb_uio > module is to provide userspace access. > > Fixes: af75078fece3 ("first public release") > > Signed-off-by: Ferruh Yigit Applied, thanks I suggested to apply it in RC3 but we have no comments. That's why it is part of RC2.